The present invention relates to a method for manufacturing a surface emitting type AlGaAs/GaAs semiconductor LASER diode by a selective epitaxy method, and more particularly to a manufacturing method of a surface emitting type AlGaAs/GaAs semiconductor LASER diode which is capable of forming naturally a 45.degree. mirror reflective face during the epitaxy process itself at the time of manufacturing a semiconductor LASER diode.
In general, since a semiconductor LASER diode is capable of forming two-dimensional array it can obtain an enormously large output more than that of one-dimensional array of edge emitting type LASER diode. Consequently, the surface emitting type semiconductor LASER diode can be widely used in the high speed signal transmission between semiconductor elements having the integration capacity more than that of VLSI (Very Large Scale Integration).
However, there has been some difficulties in manufacturing the surface emitting type element in case of AlGaAs/GaAs which is the typical kind of semiconductor LASER diode.
For example, according to a prior art method known from J. P. Donnelly et al., Appl. Phys. Lett., 51, pp. 1138, Oct., 1987, it utilizes 45.degree. mirror reflective face for the purpose of turning a beam emitted from an edge toward the surface, while it has to adopt a IBAE (Ion Beam Assisted Etching) method in order to manufacture the 45.degree. mirror reflective face, thereby giving rise to the problems that the equipment of high price is required and the yields thereof become low.
According to another prior art method suggested by K. Mitsunaga et al., Appl. Phys. Lett., 50, pp. 1788, June, 1987, it also implicates the disadvantages in that since a grating has to be formed on a layer of AlGaAs the output thereof becomes low due to the oxidation of AlGaAs layer, the uniformity of grating and the dispersion of light.
According to the other prior art method suggested by K. Iga et al., Appl. Phys. Lett., 45, pp. 348, Aug., 1987, it needs two expitaxy processes and thus the process becomes complicated, and since the reflective properties of the mirror reflective face becomes low the properties of element are not good.